1. Field of the Invention
The present invention relates to an apparatus for performing transactions such as an electronic cash register or bank machine.
2. Related Art
Many electronic cash registers (ECR's) are adapted to calculate change. The operator first keys in the price values of goods purchased by the customer, whereupon the total sum is calculated. The operator then keys in the sum of cash given by the customer (received sum). The ECR automatically calculates the change (received sum minus total sum) and displays the sum of the change. With reference to the sum displayed, the operator returns the change to the customer.
With such an ECR, the operator must always key in the sum received. Entering received sums invariably involves the likelihood of errors where large quantities of sales must be handled promptly. For example, when the customer offers 10200 yen to the operator in payment of 6200 yen, the operator is likely to incorrectly key in 12000 yen as the received sum. The change will then be shown as 5800 yen instead of 4000 yen, and if the operator believes in this value and gives 5800 yen to the customer, the store will suffer a loss of 1800 yen. Thus the conventional ECR has the drawback of executing transactions improperly owing to the operator's keying-in errors, whereas if it is attempted to manipulate the keys accurately, a reduced keying-in speed will result in lower efficiency.